Swr power meter with protection for solid state pa the. A very simple to build, menu driven rf power meter, based. Autocap integration integrating the meter into autocap was straightforward, and the software now offers to use any working sensor based on this kit. After finishing with a simple vswr plotter using an arduino pro mini and a tft, i decided to improve the rf measurement section of the analyser with an ad8307 based power rf meter. So with a 92db dynamic range, lets say you use 90db of that for simplicitys sake. Ad8307 power meter qq article additional build notes. Removing the dummy load portion of that board i was able to import the ad8307 power meter circuitry with only a little change in the original layout. Rf power meter with arduino, ad8307 and oled by rudi imbrechts. That would be 20dbspl to 100dbspl, hardly likely youll need that much. This article looks at combining the ad8307 module with a display option based on an arduino nano. Swr wattmeter with arduino uno shield resource detail. I used the arduino software from the book, and modified it to include a larger. Digital wattmeter with ad8307, pic16f876, lcd display.
I should note that this prototype uses a true nano, it contains a. Make sure the input on the ad8307 never exceeds 10mw 10dbm better. Ad8307 rf power meter probe is used to measure the strength of rf power and may be mounted in a small metal enclosure. Ad8307 rf decibel power meter circuit electroschematics. Mar 21, 2015 usb rf power meter is based on popular ad8307 watt meter ic and pic18f2550 microcontroller. The desig is simple and is popular among hobbyists. Whether we are tuning up homebrew equipment, checking antenna vswr, adjusting a linear amplifier, or just monitoring output power during a contest, almost all aspects of ham operation can use a power meter. This article describes a simple to build, yet potentially accurate digital power meter.
The hardware was kept easy, as the calibration interceptpoint, voltage per db shall be done in the software. The ad8307 puts out a voltage that is proportional to the log of the input power. An experimental rf power meter using arduino youtube. Make an arduinobased power and swr meter for amateur radio the arduino platform lends itself nicely to other pursuits, and one of these is amateur radio. Oct 16, 2015 the best way to test these would be to build a simple power meter. The power detector is an analog devices ad8307 along with a 50ohm input load. Swr power meter with protection for solid state pa page. I currently own an octocopter with 1 m span and added a camera with gimbal and a live video link to it. This instrument can be used and calibrated from 1 khz and up to 500 mhz it is possible to measure power relative all the way up to 900mhz a software routine can calibrate the 0dbm point at 5 different frequencies to. A lot of people have done the open source power meter with arduino. Nov 24, 2017 on this video i will show you how to use smd ad8307 on breadboard and use ic output to calculate signal power strength by analog vu meter.
Ad8307 module for rf power meter rssi for arduino or other. Although i bought the book and respect the of the authors i will share my own schematic here. The ad8307 voltage output connects to the arduino a0 pin. I got hold of an ad8307 in smd form, too small for me.
Code is based on sketch of mike richards g4wnc and adapted for. A preprogrammed microcontroller type pic16f876 with builtin 10bit analogue to digital. First of all, this swr meter in this article is not exactly homebrew, as i based the circuit on the schematic in the excellent book arduino projects of amateur radio. Listed under the technical reference arduino category that is about ham radio arduino projects. Usb 0500mhz rf power meter with ad8307 using pic microcontoller. Unfortunately, accurate, wideband models are fairly expensive. Is there a way to convert a square wave to a sine wave with. The adcinterrupt routine is called by the analog to digital converter each time a conversion is finished and the results are available. Ad8307 power meter the speaky hf ssb transceiver and. Because the ad8307 is frequency compensated following an article here it can be used as a mw meter in the range up to 500 mhz.
With a log amp the output voltage is a straight linear representation of wattage. What is it an rf power meter is a device which you can use to measure the power a transmitter outputs. I had the layout for the power meter part of the specam and the arduino and display that i had done for the dummy load wattmeter. Swr power meter with protection for solid state pa the pa3csg. To measure output rf power of transmitter connect ad8307 probe input directly to the output of your transmitter antenna output. The best way to test these would be to build a simple power meter. This instrument can be used and calibrated from 1 khz and up to 500 mhz it is possible to measure power relative all the way up to 900mhz a software routine can calibrate the 0dbm point at 5 different frequencies to make this instrument accurate within 0. I was looking for pic mcus and found that pic16f876 is going to nrnd, so after this i found it was the best time to start this project. You will find the schematic of the directional coupler, the schematic of the ad8307 amp circuit, the excel file i used for calibration, a diagram of the smoothing algorithm, a fritzing wiring. Even the menu functions i build in the new software. Im a member of the model aircraft c19lub fms spaarnwoude near amsterdam and i started building and flying drones. Code is based on sketch of mike richards g4wnc and adapted for use with an i2c oled display, some display functions added. Psm300040005000 rf and microwave power sensor power meter.
It measures, in one range, power from 100 nw to 100w 9 orders of magnitude covering all hf bands up to 2 metres. This link is listed in our web site directory since wednesday aug 3 2016, and till today arduino power and swr meter has been followed for a total of 3004 times. Make an arduinobased power and swr meter for amateur radio. It is not just wattmeter, it is a 3 channel power switch with meter function per each channel. If you build the meter using the same voltage reference and component values in front of the ad8307 as indicated in the diagram above, then i would expect reasonable accuracy with the parameters used by default in the firmware. The software settings can be changed to use 1050dbm attenuator and thus allowing to measure rf power higher than 2w. I have a cts crystal oscillator 50mhz mxo45hs50m000 dip8, ive read that this crystal allows me to make a signal generator of 10dbm to calibrate the ad8307 with 50 mv. Its a ad8307 rf wattmeter from oz2cpu in a pcb that can be placed on a hammond 1590b box. Ad8307 rf logarithmic power meter, keenso ad8307 rf power meter logarithmic testing detector 0. This meter had to be suitable for a large power range. Mar 19, 2020 you will find the schematic of the directional coupler, the schematic of the ad8307 amp circuit, the excel file i used for calibration, a diagram of the smoothing algorithm, a fritzing wiring.
Output is displayed in dbm, watts nw, uw, mw and w range as well as input voltage. The dds is an ad9851 running at 150 mhz and the logarithmic detector is a ad8307. It is designed to operate as an inline power meter and displays the results on a 16 digit lcd display. The better rf swr meters available these days can give very good performance using log amp detectors, with many popular designs based on the analog devices ad8307, good for a claimed 92 db range and 0500mhz bandwidth. The slug repellent tape is excellent for rf blindage, only needs to have something bellow to give some more rigidity. Rf power meter with ad8307 circuit wiring diagrams. Ad8307 power meter qq article additional build notes update 111217 i just received the latest issue of qrp quarterly with the first in a series of articles i am writing on using a building block approach for designing and building simple arduino based test equipment. New ad8307 power meter the speaky hf ssb transceiver. Why did i built it im a member of the model aircraft c19lub fms spaarnwoude near amsterdam and i started building and flying drones. I wanted a board that could be mounted in a remote enclosure or could be put in a self contained box with the rest. He used a pic to convert the dbm readings back into watts and to calibrate the device, too.
For programming changes to the nextion module, the arduino nextion library will need to be added to your library folder under your working arduino folder set. A meter that reads 5v at 100w power will have a resolution of about 100mw. So the challenge was to try some ugly construction using a piece of copperclad. Rf power meter with arduino, ad8307 and oled by rudi imbrechts on7ir january 2019.
The rf power in dbm can be read directly with a multimeter, and ive found it particularly useful for measuring rf filter response when combined with a sweep generator and an oscilloscope. Mar 16, 2018 the circuit is based on two ad8307 log amplifiers, which are connected to the forward and reflected ports on a directional coupler the ad8307 amplifiers gives a dc voltage of about 25mvdb of the input signal, which is amplified using an opamp lm324. A simple digital power meter warrington amateur radio club. Is there way to calculate the sine wave power equivalent to a 0dbm square wave. I originally set up this board to work with the circuitry in qex article may june 20 by loftur jonasson tf33ljve2ljx, squeeze every last drop out of the ad8307 log amp pp. There is no filtering on the power detector so it can measure from very low frequencies to 500mhz. Test the code in an simulated environment by simulating the input voltage with an potmeter. The ad8307 amplifiers gives a dc voltage of about 25mvdb of the input signal, which is amplified using an opamp lm324.
An diy rf decibel or power meter is an indispensable instrument in any radio workshop. Rf power meter with 1mhz10ghz bandwidth and 55db dynamic. Arduino code for 0500mhz, 1nw to 100w rf power meter mike. As you may notice, there are no buttons on the device. Using ad8307 log amplifier for sound level meter arduino. I used the arduino software from the book, and modified it to include a larger display and some other things. What is it an rf power meter is a device which you can use to. A milliwatt to kilowatt rf power meter using the analog devices ad8307 a friend of mine, dick benson, w1qg, built a pretty cool combined forward and reflected power and swr meter using two ad8307 logarithmic amplifier chips from analog devices. The driving part of the program is the adcinterrupt routine. A word of warning when copying this code the arduino software doesnt like the marks when they are copied, you need to replace all of them by physically typing the into the program. It is based on a pic 16f876a and an ad8307 logarithmic detector. This was my first smt design, and i am fairly happy with the result. Oct 22, 2015 an rf power meter is a device which you can use to measure the power a transmitter outputs. Arduino code for 0500mhz, 1nw to 100w rf power meter.
Apr 21, 2014 here is yet another ad8307 based rf power meter which adds an opamp to produce a dc output voltage of 1mvdbm e. Dec 05, 2015 homebrew swr and power meter first of all, this swr meter in this article is not exactly homebrew, as i based the circuit on the schematic in the excellent book arduino projects of amateur radio. I always wanted to build a rf wattmeter with the ad8307 and oz2cpu design. If i apply a square wave with 0dbm, what will be the sine wave power read by the ad8307. About arduino power and swr meter the resource is currently listed in in a single category. In the future it will probably be an full scale swr monitor.
Make an arduino based power and swr meter for amateur radio the arduino platform lends itself nicely to other pursuits, and one of these is amateur radio. Pwr10rmsrc, 1mhz10ghz, usb power sensor, ad8319, succobox, arduino micro. Usb rf power meter is based on popular ad8307 watt meter ic and pic18f2550 microcontroller. Instead of using lcd display module the meter connects to a pc via usb port and displays measurements on a computer via usb rf power meter software. I started it from scratch and decided to build an accurate power meter for the directional coupler described here. The main category is ham radio arduino projects that is about arduino projects for ham radio applications.
Because of the pic compiler constraint to make the necessary changes in the source, i decided to step over to the arduino nano. The measurand quantity to be measured is applied to pin 8 inp of ic1 via input socket k1 and capacitor c1. The circuit diagram of the decibel meter in figure 1 stands out by its simplicity, which is due to the type ad8307 monolithic demodulating logarithmic amplifier, ic1, from analog devices. Last weekend i started building a rf power detector with an ad 8307 log amp. The ad8307 output is connected to an arduino analog input and computation is done in software, with output to the lcd and usb line. I build the same display layout as from the oz2cpu meter because i liked that. Transfer the code from funduino uno board to a arduino mini board. Its a mix from the datasheet and from the circuit in emrfd experimental methods for rf design, the ad8307 part of the diagram is from datasheet and the opamp parts is from emrfd placed an 68k resistor in series with my 100ua meter in the original.
This link is listed in our web site directory since thursday sep 26 20, and till today swr wattmeter with arduino uno shield has been followed for a total of 7300 times. Is there a way to convert a square wave to a sine wave with the same power. A very simple to build, menu driven rf power meter, based on. Also a voltage reference was needed, see the software part. Calculating swr with rf directional couplers arduino. Here is yet another ad8307 based rf power meter which adds an opamp to produce a dc output voltage of 1mvdbm e. Keep this in mind as you set the full scale voltage of your transducer. This swr power meter was my first own project for the arduino. C1 and this rf wattmeter uses an ad8307 to measure the power level. Oct 25, 2015 after finishing with a simple vswr plotter using an arduino pro mini and a tft, i decided to improve the rf measurement section of the analyser with an ad8307 based power rf meter. About swr wattmeter with arduino uno shield the resource is currently listed in in 2 categories.
Ad8307 module for rf power meter rssi for arduino or other mcu or standalone a. Jun 24, 2015 output is displayed in dbm, watts nw, uw, mw and w range as well as input voltage. Copy and paste the code below into your arduino ide. Besides i have modified the software, i removed the ssb meter, swr meter, about. The ad8307 front end circuit is both frequency compensated and optimised for return loss to give optimum input swr over a wide frequency range. To do this, all the meter needs is two accurate signal levels, 30 40 db apart, as calibration points. Portable rf sniffer and power meter paul wade w1ghz 2003, 2004 rf power meters are extremely useful instruments. It consists of from left to right the 5v power supply, the arduino nano, the ad8317. In the software you can enable the alarm function and the limits for the alarm settings. I wanted a board that could be mounted in a remote. Some people who built the power meter came with some good ideas and.